This study cross-validated the dot counting test (DCT) as a performance validity test (PVT) in an adult attention-deficit/hyperactivity disorder (ADHD) clinical population and examined the effect of ADHD subtype and psychiatric comorbidity on accuracy for detecting invalidity. DCT performance was assessed among 210 consecutive adult ADHD referrals who underwent neuropsychological evaluation and were classified into valid (n = 175) or invalid (n = 35) groups based on seven independent criterion…